I've stumbled across your show and personal beliefs aside, I just have to say that people are really stupid. As a Catholic, I'm ashamed of the logic of Christians trying to prove the existence of God as it presents itself on your show. I do have a question which I don't get about what atheists state: God can never be proven through science. If something exists, it can be proven. Yet with the logic that the Christians use, they change Christian belief and twist it into personal assumptions rather than going by fundamental doctrine. I guess my questions are: 1) Why can't science ever prove God? ; 2) What, besides God walking up to you, can be proof for the existence of God?
And by God, I mean a physical entity that can come down and walk amongst us, wrestle with us and looks like us. Basically, if you stood next to God, you'd see that humans were created to be in the image of God. I know how you love to get definitions of God.
You have to understand that we can only respond to claims that we are offered about God, and there are thousands of conflicting versions of God. I know many atheists have put forth the case that God should be possible to investigate through science, and have suggested specific ways that the claim could be testable.
However, to understand how much the waters have been muddied, you ought to familiarize yourself with the history of the creationism movement. A hundred years ago, it was illegal to teach evolution in schools at all. By the 1960's, evolution was accepted as standard science. However, there was a movement to demand that creationism must be taught as science by law. This was finally rejected because creationism, at the time, was considered purely religion with no scientific merit.
So in the mid 60's there was a push to create "scientific creationism." At the time, creationists still attempted to make testable claims, generally centered around a literal interpretation of the Bible. For instance, they attempted to prove that the global flood was real. But the problem with such specific claims is that science can not only test them; it can prove them wrong. And it did, which eventually led to more legislative defeats for creationists.
Since that time, creationists have gotten a lot more crafty in trying to advance a watered down form of creationism in schools. The 1990's saw the rise of "intelligent design" which, while heavily borrowing elements of traditional creationism, made the definition of "the designer" continually more vague and without specific testable claims. In their effort not to be labeled as yet another drive to teach religion in schools, they refuse to say anything specific about God. They just say "we logically infer that there must be a designer" and they don't propose any claims about what the designer is like or how he could be tested.
This achieves the objective of being harder to counter with observable facts, yes, but it also renders meaningless any efforts to actually investigate "God" or some other sort of designer.
So can science investigate God? It depends, of course. If the concept of God is attached to specific claims about the way he interacts with the world, then yeah, you're right, that God should in principle be testable. Of course, no scientific investigations have ever revealed anything like the God of the Bible.
But on the other hand, when people propose a God that is deliberately made vague, that is untestable. An amorphous "intelligent designer" can't be investigated, and as I've explained, that is pretty much on purpose. Likewise, vague claims like "God is love" or "God is a universal consciousness" don't lend themselves easily to testing. If we ever said that God is not a scientific concept, you can bet that we were probably responding specifically to a person who was advancing this kind of nonspecific notion of God.
As for your second question: "What, besides God walking up to you, can be proof for the existence of God?" Well, I mean, God walking up to me would be a pretty good one. It's not even all that outlandish a request. After all, according to the Bible, God used to appear to people all the time. He talked to Moses in a burning Bush, he showed his puncture wounds to Doubting Thomas, he dropped in on Saul of Tarsus, he told Abraham to kill his son (before going on to say "just kidding!").
If God is bothered by the existence of atheists, then clearly he knows how to fix that. What's weird is that God is seemingly so selective. A few scattered people get to have a fireside chat with God. The rest of us apparently have to make do with clearly apocryphal stories about the appearances, and believe blindly with no such concrete evidence whatsoever. If this is the way God works, then either he enjoys playing mind games with the millions of atheists on the planet, or else he really does want them to remain atheists.
As for me, I don't think there is a god. If it turns out I'm wrong, he knows where I live.